It is known that the current touch panel has a central sensing area and a peripheral wire area. The sensing area has a plurality of touch sensors which is formed as a pattern. The wire area has a plurality of signal wires which are connected to the touch sensors, respectively so as to form as signal loops. In operation, by the finger of the user to touch the sensing area of the touch panel to induce a capacitive induction signal and a resistor induction signal. The variation of the capacitance and resistance will indicate the position of the finger and the conductor.
Currently in the manufacturing method for touch sensor pattern and the signal wires, referring to FIG. 9, a Mo/Al metal plating film 101 and an ITO plating film 102 are coated on a transparent substrate 100. A yellow light process is applied to the substrate for coating a layer of light resistor thin film 109 on the substrate (referring to FIG. 9). Then the substrate is placed to a furnace for heating. Then a mask 601 with a precision wire pattern is used to exposing the light resistor thin film 109 (referring to FIG. 10). Then the developing agent is applied to the light resistor thin film 109 for solidifying the exposing area. Next cleaning agent is used clean the un-exposing area of the light resistor thin film 109 so that the remove the light resistor material on the light resistor thin film 109 and a layer of solidified light resistor thin film FP (referring to FIG. 11) is formed on the un-exposing area (referring to FIG. 11). Then a further yellow light process is further applied to the substrate. Then, an etching agent suitable for Mo/Al metal film is applied to the substrate for etching out the Mo/Al metal plating film 101 not shielded by the light resistor thin film FP so as to retain the pattern of the signal wire 107 (referring to FIG. 12) on the light resistor thin film (referring to FIG. 12). Then a film removing agent is applied to the light resistor thin film FP on the substrate. Then cleaning agent is used to clean the substrate so as to expose the signal wire 107 on the Mo/Al metal plating film (referring to FIG. 13).
Then a second yellow light process is applied. That is, a layer of light resistor thin film 109 is coated on the upper surface of the substrate (referring to FIG. 14). Then the substrate is placed to a furnace for preheating. Next, a mask 602 with precise patterns of the sensing area and wire area is used to expose the light resistor thin film 109 (referring to FIG. 15). Then the developing agent is applied to the light resistor thin film for solidifying the exposing area. Next cleaning agent is used clean the un-exposing area of the light resistor thin film so as to remove the light resistor material on the light resistor thin film 109 and a layer of solidified light resistor thin film FP (referring to FIG. 16) is formed on the sensing area 103 and wire area 104. Then a further yellow light process is further applied to the substrate. An etching agent for ITO thin film is applied to the substrate for etching out the film not shielded by the light resistor thin film FP so as to retain the pattern of the touch sensor pattern 106 and signal wire 107 (referring to FIG. 17) on the light resistor thin film. Then a film removing agent is applied to the light resistor thin film FP on the substrate. Then cleaning agent is used to clean the substrate so as to expose the touch sensor pattern 106 on the ITO film and the signal wire 107 on the Mo/Al metal plating film (referring to FIG. 18).
In above mentioned process for touch sensor pattern and the signal wires, the first yellow light process and the first etching process are used to form the signal wires 107 on the Mo/Al plating film 101. Then the second yellow light process and the second etching process are used to form the touch sensor pattern 106 on the ITO plating film 102. Therefore, it is known that in the prior art, the yellow light processes and wet etching processes are used. Each process contains the steps of coating light resistor, preheating, exposure, development, etching, filming removing, etc. The process is tedious and the yield ratio is low. In fact it is known that in this prior art, the yield rate is about 70%. It is necessary to be improved.